Zionsville, Indiana has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 43.3 °F (low) to 61.9 °F (high). Annual precipitation averages 43.3 Inches. Zionsville is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 19.9 °F | 35.2 °F | 2.94 in. |
| February | 22.6 °F | 39.2 °F | 2.48 in. |
| March | 31.4 °F | 50.0 °F | 3.28 in. |
| April | 42.2 °F | 62.8 °F | 4.43 in. |
| May | 53.3 °F | 72.8 °F | 4.69 in. |
| June | 62.2 °F | 81.2 °F | 5.18 in. |
| July | 65.3 °F | 84.2 °F | 4.29 in. |
| August | 63.6 °F | 83.1 °F | 3.12 in. |
| September | 55.9 °F | 77.7 °F | 3.33 in. |
| October | 44.4 °F | 65.5 °F | 3.18 in. |
| November | 33.9 °F | 51.3 °F | 3.42 in. |
| December | 25.1 °F | 39.6 °F | 2.97 in. |
| Annual | 43.3 °F | 61.9 °F | 43.31 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |